Improvement in steam-engines



Uivrrnn SrAEEs PATENT. LOGEEIGE.

JAMES R. MAXWELL AND EZE; COPE, or GINGINNA'H, oHro.

nviPRovEMENT VINg STEAM-ENGINES.

'To allwhom yt mcg/concern: ,y i

Be it known that we, JAMES It. MAXWELL and EZEA COPE, of Cincinnati, in vthe county of Hamilton and State of Ohio, have invented a new and Improved Steam-Engine; and we hereby declare the following to he a full, clear, andexact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon. t 1

Figure l is a perspective view ofthe steamcylinder. Fig. 2 is a longitudinal and verti` cal section of the same. Fig. 3 is a cross-sec tion through the line 1 and 2, Fig. 2. Fig. 4 is a perspective view of the rocklshaft E, inclined arms M M', arms J and H, rock -shaft G, finger N, hollow cylindrical slide-.valve G,

with its ports at X', X, Y, and Z, and h', holes h" and I, spiral groove O, chamber It, and wrist pin L. Fig. 5 is a vertical crosssection through the valve-chest and throttlevalves, on line 7 and 8, Fig. .6, showing the steam-pipe a, throttle or regulafingvalves b b, steam-ports .to valve C a a', exhaust-port Z and f, small exhaust-ports h' h' from valve, port h in Valve, also steam-ports wand y, and partition S'. Fig. 6 is a longitudinal section through the lines 3 Yand 4, Fig. 3, and 5 and 6, Fig. 2, showing the valve-chest C', ports a a', the hollow cylindrical slide-valve '0, with its ports rv, y, and z, chamber R, holes I I, and partition S'. Fig. 7 is a plan view of the joint between the steam-cylinder A and the valvechest C, at S, Figs. 1, 2, 3, and 5, showing the steam-ports to the main cylinder at g g, the

main exhaust-port at f, and the exhaust-ports from the valve-chest ath h'.

We make the main steam cylinder in the usual manner, except that there is provided a stuffing-box at each end to receive the rockshaft E parallel to the cylinder. Each end of the rock-shaft E is made to carry an arm with an oblique surface extending into the interior of the cylinder, in position to be moved outwardly by the piston alternately as its stroke terminates. The arm J is also secured on the rock-shaft E, to engage, by means of wrist-pin and slot, with the arm H, secured on the rockshaft Gr, which enters the valve-chest through a stufling-box, and is connected with the valve C by having a full end-bearing within the valve, and a linger, N, litted to work lin a short diagonal or spiral groove formed within the valve.

specification formingpart pfLeaers remit No, omoiftiited Augst 24, 1869.

Theihollo'w cylindricalv slide-valve Chas one small steam-port, I, additional at each end, to pass steam from the interior of the valve tothe valve-chest or chamber 0'; also two exhaust ports or openings, made larger than the small steamfports just described, one commencing at each end, coming to the surface at h'Fig. 4, but

on oppositesides and ends. The surface-openings are of a length equal to the play ot' the valve,l `and communicate, through the ports h' h' formed in the lower part of the valve-chamber C', with the main steam-ports g gleading an upright or inclined pumping-engine. Thenthetwo throttle valves b b control and regulate the tlow of steam admitted through the separate passages aa' to their respective ends of the steam-cylinder; but-'in cases where no vsuch unequal dutiesv are required, we make,

as ordinarily, one throttle valve and steampassage to suffice, and dispense also. with'the .partition S' in the valve.

In Fig. l the rock-shaft E is shown to pass through two stuting-boxes, P P, with the arm J placed between them, which plan we prefer for engines of long stroke; butl for engines of short stroke the rock-shaft E can'be surrounded .by the metal of the cylinder for its whole length, and extend through'the cylinder-head and stuling-box thereon; then the arm J, with its engaging-arm H, can .be arranged clearof the length of the steam-cylinder. In this construction the shortest connection with a pump can be had, requiring merely room for the piston-rod glands and packing. The rock-shaft and its arms may be connected to and operate with the pump-cyl inder and piston in like manner.

To operate our engine, steam is admitted at c", Figs. 1, 2, and 5, and passes in the direction of the arrows through the regulating; valves b b into the valve C. The main piston B, Fig. 2, has completed its stroke in one direction, and is at the point of beginning its stroke in the reverse direction, as indicated by the arrows. The steam is being supplied through the relating ports, and passes :v in the valve C andh g into the cylinder. The valve Gis also moving in the same direction, as shown by the arrows, while the exhauststeam is escaping fromV the-opposite end of the cylinder through the relating ports, and- 3,. 4, and 5, which will allow the steam to passl lfreely from the valve-chamber into the exhausting end of the steam-port g', thus unbalancing the steam-pressure on the ends of the valve, moving it in the opposite direction to the piston, changing the steam, and reversing the'piston continuously as long as the steam is supplied. The contact of the piston with the arm M' at the other end of the shaft E alternate the movements described.

The oice of the small ports' I l is to pass steam continually to the ends of the valvechamber, preserving the balance of pressures on each end of the valve until the motion of the valve, first proceeding from the rock-shaft E, opens communication through the ports h" h with the interior of main cylinder on the exhaust side of the piston,lwhen the valve wll'be in proper position and relation to the pressures to be reversed, and to direct the main flow of steam through the ordinary ports and passages a: and g to the sameside of the piston at the termination of its stroke, producing the equilibrium of pressures upon the lends of valve, and affording a perfect cushion to the end movement of the valve. The return or travel of the valve on the reverse movements brings all the ports and passages belonging -to the opposite ends of the valve andcylinder in relation, the pressures on the ends of the valve become unbalanced by the escape of steam through the port h" and passages to the exhaust side of the piston, until the valve is in position andchanges the direction of the main iow of steam to the exhaust side of piston, to begin the stroke in the opposite direction, when the pressures on the ends of the valve again become balanced, and the whole set of movements alternated.

The oice of the diagonal groove O in the valve is to continue the motion of the valve initiated by the rock-shaft E further around than the throw of the nger N rst accomplishes, in order to more fully open the exhaust-ports, and thus insure more promptness of action in the valve when the engine is moving slow.

It' the character of the duty required of the engine be suchg-.as to need one pressuretfor the direct stroke, and a greater or less press'- ure for the reverse stroke, the amount of steam admitted to each end isvaried and regulated by the two throttle-valves b b, Figs. 1,

.3, and 5, adjusted to control the low of steam,

each separately to theV end of steam-cylinder, respectively, as they belong.

Having fully described the construction and loperation of our invention, what lwe claim, and desire to secure by Letters Patent,

1. The rock-shaft E, parallel to the cylinder, actuated by contact of oblique surfaces of the arms MM thereon andthe piston within the cylinder, constructed, combined, and arranged as herein set forth.

2. The rock-shaft E and the valve C, having a diagonal groove, O, in combinationwith their intervening gear, substantially as described.

3. The rock-shaft G- and the finger N, in combination with the diagonal groove O, substantially as described. v

4. The valve C with the steam-supply" openings I I', exhaust-openings h' h', constructed and arranged with reference to the chamber C C, and the induction and eduction ports thereof, substantially as described.

5. Thesteam-cylinder A, in combination `with the two separate throttlel or regulating valves b b, arranged to control the flow and quantity of steam admitted throughseparate passages, respectively, to each end of the steam-cylinder, substantially as described. Y

JAMES n. iymxwiiznn.Y EZRA corn.

Attest N. MARCHANT, F. MARCHANT. 

